2. Normal Physiology
• Total body water is 60% of body weight in males, 50% of body
weight in females, i.e. 30 litres
• Intracellular water - 20 litres (2/3).
• Extracellular water - 10 litres (1/3).
- Plasma (1/4) (2.5 litres).
- Interstitial fluid (7.5 litres).
3. Normal Physiology
• ECF volume and osmolality regulation is controlled by three hormones.
• Aldosterone, ADH, atrial natriuretic hormone.
Ion ICF ECF and plasma
Sodium 10 mmol/L 140 mmol/L
Potassium 150 mmol/L 4.5 mmol/L
Chloride Trace only 105 mmol/L
4. WATER LOSS (VOLUME LOSS )
• It is decrease in the whole body fluid volume which includes both ECF
and ICF.
• It is usually ECF loss which is more important and assessed.
• It can be isotonic volume depletion with both salt and water loss leading
into hypovolaemia, or only water loss with only minimal loss of
electrolytes leading into dehydration.
5. Causes and Features
• Isotonic volume depletion occurs due to diarrhoea, vomiting, and
excess diuresis
• Here normal or decreased sodium is observed
• This causes hypotension and decreased tissue perfusion.
6. Causes and Features
• Dry tongue, rapid pulse, cold clammy extremities, sunken eyes,
hypotension, oliguria, raised blood urea, decreased urinary sodium.
• Hypovolaemia can be mild (< 2l fluid loss); moderate (2–3 L fluid
loss); severe (>3 L fluid loss).
7. Causes and Features
• Only pure water loss occurs due to poor fluid intake and diabetes
insipidus.
• It causes dehydration with proportionate decrease in total body water
(2/3rd ICF, 1/3rd ECF)
• As ECF including intravascular fluid loss is less, hypotension is less
8. Causes and Features
• Severe thirst, confusion and convulsions due to hypernatraemia;
blood pressure is relatively normal.
• Dehydration can be mild (weight loss 5%); moderate (10%); severe
(15%).
9. Management
• Evaluation is done by doing serum sodium, urinary sodium, and
blood urea.
• Isotonic volume depletion is corrected by 0.9% normal saline.
• Pure water depletion is corrected by more water intake/ intravenous
5% dextrose.
• Monitoring fluid therapy by skin and tongue examination, weight
gain, pulse, blood pressure, CVP, PCWP.
10. WATER EXCESS (ECF VOLUME EXCESS)
• It can be divided into water and salt excess or
predominantly water excess called as water intoxication.
• Water and salt excess occurs in CCF, cirrhosis,
nephrotic syndrome, hypoproteinaemia, renal failure,
excessive saline infusion.
11. WATER EXCESS (ECF VOLUME EXCESS)
• Water intoxication occurs in TURP, excess infusion of 5% dextrose
only, SIADH secretion, psychogenic polydypsia.
• It is managed by stopping fluid infusion or procedure (TURP); fluid
restriction, and treating the cause.
12. Causes
• Excessive amount of intravenous dextrose (5%).
• During colorectal bowel wash for preparation of large bowel for
surgery, if water is used instead of saline, especially in children.
13. Causes
• In TURP (Transurethral resection of prostate) when excess irrigating
fluid water or glycine is used (commonly used).
• In syndrome of inappropriate antidiuretic hormone (SIADH) which is
commonly associated with lobar pneumonia, empyema, oat cell
carcinoma and head injury.
14. Clinical features
• Drowsiness, weakness
• Convulsions and coma
• Nausea, vomiting
• Passage of dilute urine
• Distended neck veins
16. Treatment
• Water and salt restriction and observation.
• Monitoring in ICU.
• Management of fluid and electrolyte balance.
• Infusion of hypotonic sodium chloride.
17. Treatment
• Administration of diuretics and hypertonic saline should be avoided,
as it may cause rapid changes in serum sodium and water level
which will lead to neuronal demyelination and fatal outcome.
18. ECF LOSS
• Here only ECF loss is present with normal ICF.
• It is seen in vomiting, diarrhoea, intestinal obstruction.
• Treatment is infusion of normal saline.
19. ECF EXCESS
• Only ECF excess without an ICF excess.
• Excessive infusion of saline with impaired excretion.
• Raised JVP (earliest and best clinical sign), cardiac failure and
peripheral oedema.
• Treatment is fluid restriction and diuretics like frusemide
20. ECF EXCESS
• Only ECF excess without an ICF excess.
• Excessive infusion of saline with impaired excretion.
• Raised JVP (earliest and best clinical sign), cardiac failure and
peripheral oedema.
• Treatment is fluid restriction and diuretics like frusemide
